1. Field
This invention relates to the field of telecommunications, and in particular, a method of distributing telephone identity associations to one or more telephones systems in a telephone network.
2. Related Art
A typical telephone network, such as the Public Switched Telephone Network (PSTN) or a corporate telephone network, comprises one or more telephone systems. Each telephone system within a telephone network is assigned to handle a certain set of telephone numbers. Within a given telephone system, each telephone number can be assigned to a telephone. A user (caller) can uses his telephone to dial the telephone number of another user (callee). Often the telephones of the caller and the callee are connected to two different telephone systems within the telephone network. For example, it is possible that the caller is on the West coast using a local telephone system and the callee is on the East coast using yet another local telephone system. In order to complete such a call, it is common for the call to be routed through a number of telephone systems before reaching the telephone system responsible for handling the telephone number associated with the callee's telephone. For each call, all participating telephone systems within the telephone network must determine whether or not it is responsible for the called telephone number or whether the call should be passed on to another telephone system based on the telephone number dialed and other factors and attributes of the telephone number. In the event that a given telephone system is responsible for handling a given telephone call, then the telephone system will connect the call to the telephone associated with that particular telephone number.
To properly route a call, each telephone system within a telephone network needs a way to determine which telephone system can reach a particular telephone number. According to the current state of the art, a typical solution is to manually configure every telephone system with all possible associations of telephone numbers and telephone systems. This means that for every valid telephone number there would need to be a record with that telephone number and the telephone system with which it is associated. The drawback with manual configuration of each telephone systems is that when a telephone system adds, changes, or deletes a telephone number or a range of telephone numbers, the new information is not automatically shared with other telephone systems. The administrative authority of the telephone system making changes must inform the administrative authority of other telephone systems to make corresponding changes. Such procedures are often completely manual, error-prone process and expensive to maintain and expand.
The manual change process described above can be acceptable when changes are infrequent or where telephone systems and telephone numbers are added, deleted or changed only once in a great while. However, the recent adoption of Voice Over IP (VoIP) services, telephone number portability services, and mobile telephone services, has spurred rapid expansion of the number and variety of telephone systems and a surge in changes to telephone identity associations which describe and define the association between telephone numbers to telephone systems. Manual methods of managing telephone identity associations become significant bottlenecks and represent significant costs to maintain existing services and roll out new voice and communication services.
A typical telephone network comprises multiple telephone systems. Each telephone system in a telephone network has a telephone system identity that uniquely identifies that particular telephone system. FIG. 1 illustrates a telephone system in a telephone network. A telephone system 100 can connect to other telephone system 190. Each other telephone system 190 is a telephone system.
Telephone system 100 can connect to one or more user terminals 110. Telephone system 100 connects to user terminal 110 when a user plugs user terminal 110 to a wall telephone jack of telephone system 100. Similarly, telephone system 100 disconnects from user terminal 110 when a user unplugs user terminal 110 from a wall telephone jack of telephone system 100. In certain scenarios, telephone system 100 connects to user terminal 110 when user terminal 110 registers with telephone system 100. Similarly, telephone system 100 disconnects from user terminal 110 when user terminal 110 deregisters from telephone system 100. Often telephone system 100 can determine that telephone system 100 connects to user terminal 110 when telephone system 100 detects certain signals from user terminal 110. The signals can be part of an automatic discovery procedure. In another scenarios, telephone system 100 determines that telephone system 100 disconnects from user terminal 110 based on certain criteria. Such criteria can include, but is not limited to, the loss of communication between telephone system 100 and user terminal 110 for 10 or 50 minutes.
A user terminal 110 can have one or more telephone numbers. Often an operator of telephone system 100 assigns a telephone number to a user terminal. A telephone number becomes reachable by telephone system 100 when an operator provisions the telephone number in telephone system 100. Likewise, a telephone number becomes unreachable by telephone system 100 when an operator deletes the telephone number from telephone system 100. It is also possible for a telephone number to become reachable by telephone system 100 when a user terminal 110 that has the telephone number connects to telephone system 100. The same is true of the reverse; a telephone number becomes unreachable by telephone system 100 when a user terminal 110 that has the telephone number disconnects from telephone system 100.
User terminal 110 includes components that allow a user to place calls to and receive calls from other users using other user terminals. User terminal 110 can be a residential telephone, a mobile telephone, a corporate desk telephone, or a personal computer running a telephony application equipped with a speaker and a microphone. User terminal 110 can connect to telephone system 100 over various telephony technologies, such as POTS, ISDN-BRI, GSM, CDMA, SIP, H.323, or proprietary digital set protocols.
A user can use user terminal 110 to enter a telephone number to make a call. User terminal 110 sends a call request to telephone system 100 for call processing. The call request includes, but is not limited to, the telephone number. Telephone system 100 includes functionality to process a call request. Telephone system 100 retrieves the telephone number included in the call request and determines how to complete the call request. In certain implementations, telephone system 100 can be an IP-PBX (IP-Private Branch Exchange), a Class 5 switch, a Class 4 switch, a tandem switch or a PBX. In a different scenario, telephone system 100 receives a call request from an other telephone system 190. Telephone system 100 handles the call request in a similar manner.
The above illustrates the need for a method of automatically distributing telephone identity associations of a telephone system to other telephone systems in a telephone network.